A PI DM 



219 



2. Hemiptera. 



The Hemiptera (Chapter XXXI., p. 761) include the families of 

 the Clinocoridse, or bugs, and the Reduvidae, or cone noses. In the 

 latter family is classified Phonergates hicoloripes Stal, which, accord- 

 ing to Wellman, produces a very painful bite in man in Angola. 

 Another member of this family, as yet not named, has been described 

 by King in the Sudan, where it bites human beings on the hands 

 and wrists, producing small red lumps, which, however, soon dis- 

 appear. It is said to be closely related to Phonergates hicoloripes. 



Bugs. — ^These hemipterons secrete a strongly alkaline poisonous 

 secretion in their salivary glands. This poison flows down the 

 ducts of the stylets, and passing into the wound made by the bite, 

 dilates the capillaries, causing an increase of blood in the area 

 bitten. This, of course, is advantageous to the insect, allowing it 

 to obtain a quantity of blood in a short space of time^ Clinically 

 the poison causes red blotches and local swellings. 



It is, however, more convenient to discuss these venomous insects 

 along with other parasites in Chapter XXXI., p. 761, as it enables 

 a more systematic description to be given, especially as the nature 

 of the venom is quite unknown. 



3. Hymenoptera. 



In this order come the bees, wasps, and ants. 



APID^. 



The members of this family which sting are well known, and it 

 is by no means infrequent to hear of animals and even at times 

 human beings in the tropics suffering severely from bee-stings, and 

 • more rarely dying from the effects. 



The species generally credited with evil effects are: Apis mellifica 

 L., the hive-bee; Vespa vulgaris L., the wasp; V. germania Fabr. ; 

 V. crabo L., the hornet; F. orientalis, the hornet; Bombus hortorum 

 L., the bumble-bee; B. lapidarius L., and Xylocopa violacea, the 

 wood- bee. 



Historical. — The venom of the bee was first studied by Brandt 

 and Ratzeburg in 1833, then by Paul Bert in 1865 and Carlet in 

 1884, but the chemical nature was first investigated carefully by Josef 

 Langer in 1897, and in 1904 Phisalix made experiments on sparrov\^s. 



Anatomical.- — The body of the bee is divided into head, thorax, 

 and abdomen, from the posterior end of the last of which projectr. 

 the sting in the form of a chitinous sheath, narrow posteriorly and 

 wider anteriorly. This sheath contains two barbed darts, and into 

 its wider portion (which possesses a cleft by which air can penetrate 

 into it) two or three ducts from glands open. The principal 

 opening belongs to the duct of the ' acid gland,' and opens an- 

 teriorly into a sac — the poison reservoir — which leads into a 

 long, slender, coiled tubular gland, either bifid anteriorly or sub- 

 divided into two glands. This long gland ramifies amongst the 



